In phloem transport, whether protoplasmic activity participates in assisting sap flow in sieve element_companion cell complex has long been in debate. The present investigation assumed microfilament (MF) and microtubu...In phloem transport, whether protoplasmic activity participates in assisting sap flow in sieve element_companion cell complex has long been in debate. The present investigation assumed microfilament (MF) and microtubule (MT), the two constituents of the protoplasmic cytoskeleton, as motive force, and employed germinating pea seedling suspended in moist chamber as experimental material: the seed being the source; the elongating root, the sink. 14 C_labeled sucrose was added to the seed as indicator. The amount of sap transported from source to sink was measured by the increase in root elongation. The transport phloem was within the cylinder of the peeled root in the middle. The exposed cylinder was treated with MF inhibitor (cytochalasin B), or microtubule inhibitor (amiphos_methyl). Results showed that the sap influx into the elongating root, and the 14 C activity as well, was reduced by about one half in treatment with cytochalasin B, and much less by amiphos_methyl treatment. Similar effect was shown in electrical impulse treatment, which seems to disrupt the MF and MT configuration.展开更多
采用同位素双标记技术 ,通过研究各种处理的棉花果枝韧皮部14 C -同化物和3 H -H2 O的运输情况 ,计算并比较二者的加权速率平均值 ,说明了韧皮部同化物和水存在一定程度的相对运动 ,这种相对运动可能是由于3 H -H2 O和筛管外细胞及胞间...采用同位素双标记技术 ,通过研究各种处理的棉花果枝韧皮部14 C -同化物和3 H -H2 O的运输情况 ,计算并比较二者的加权速率平均值 ,说明了韧皮部同化物和水存在一定程度的相对运动 ,这种相对运动可能是由于3 H -H2 O和筛管外细胞及胞间隙中的大量存在的非标记水发生侧向交换的结果 。展开更多
文摘In phloem transport, whether protoplasmic activity participates in assisting sap flow in sieve element_companion cell complex has long been in debate. The present investigation assumed microfilament (MF) and microtubule (MT), the two constituents of the protoplasmic cytoskeleton, as motive force, and employed germinating pea seedling suspended in moist chamber as experimental material: the seed being the source; the elongating root, the sink. 14 C_labeled sucrose was added to the seed as indicator. The amount of sap transported from source to sink was measured by the increase in root elongation. The transport phloem was within the cylinder of the peeled root in the middle. The exposed cylinder was treated with MF inhibitor (cytochalasin B), or microtubule inhibitor (amiphos_methyl). Results showed that the sap influx into the elongating root, and the 14 C activity as well, was reduced by about one half in treatment with cytochalasin B, and much less by amiphos_methyl treatment. Similar effect was shown in electrical impulse treatment, which seems to disrupt the MF and MT configuration.
